Emission in the 0.3 to 1.0 MeV range from the Galactic Center region

The University of New Hampshire's Large Scintillator Gamma Ray Telescope observed the Galactic Center region on 21-23 November 1977, ten days after a similar observation by the Bell and Sandia Laboratories'1 high resolution Ge gamma ray telescope. The UNH measurements are consistent with line emission near 511 keV with a flux that is at least twice as intense as the earlier measurement. The measurement requires a line intensity of (4.0 +- .6) x 10-3 γ cm-2 s-1 and a flat spectral feature in the energy range 300 to 511 keV consistent with 70--80% β+ annihilation from ground states of positronium